The European Union is not very happy that invited the Americans to visit Europe almost 2 months ago, but the USA have not returned the favor - EU citizens still can't visit the USA (not sure about Canada).
So the present game is to convince US authorities to let the European visitors in, much more than stop Americans from coming to Europe, which wouldn't be good for the economy. But if USA won't change their policy soon, there is a
potential chance that at the end of August the United States (possibly Canada as well) can be removed from the list of 'safe countries'.
That doesn't automatically mean that Spain will ban Americans from coming. It is only recommendation from Brussels for the EU countries, not a binding law.
But if I were an American planning to come to walk the Camino in Spain in September, I would probably try to choose a flight directly to Spain, rather than transiting France, just to cut the risk of any possible problems by half (one EU country instead of two)
But let's hope for the best
There's good chance that USA soon let the vaccinated Europeans in, and this transatlantic tug of war will have a happy ending